The present disclosure relates to the field of molds for curing or vulcanizing vehicle tire, and more particularly molds of the sectored type.
This type of mold mainly comprises two shells that each mold one of the lateral sidewalls of the tire, a plurality of sectors that mold the tread of said tire and are radially movable between an open position and a closed position of the mold, and at least one clamping ring for allowing the sectors to move radially.
The shells and the sectors define an inner space that is intended to be brought into contact with the unvulcanized green form of tire. For more details concerning such a type of sectored mold, reference may be made for example to the documents DE 1 808 811, U.S. Pat. No. 3,797,979, EP-A2-0 701 894 and EP-B1-2 040 911.
The manufacturing of the tire, and more particularly the vulcanization phase, requires that a pressure is applied to the green tire in order to press it against the internal faces of the mold and that heat is supplied to the mold. For example, it is known practice to heat the mold by means of a heat-transfer fluid such as pressurized water vapour, as is described in the Patent Application EP-A1-2 072 235.
It is also known practice to heat the mold electrically or else by magnetic induction, as is illustrated in the document JP-A-2012-25126. In that document, first heating means are mounted on the shells radially on the inner side of the mold and second heating means are mounted both on the shells and on the sectors.
The heat is thus produced directly in the mold, thereby making it possible to obtain satisfactory energy efficiency. Moreover, such mounting of the magnetic induction heating means promotes the obtaining of a uniform temperature in the mold.
However, in order to optimize the curing of the tire, it is necessary to heat the two shells of the mold to and keep them at a temperature different from that to which the sectors are heated. Moreover, it may also be necessary, for each of the shells, for separate regions to be heated to and kept at different temperatures.